1,351 research outputs found

    Reversibility and Improved Hydrogen Release of Magnesium Borohydride

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    Desorption and subsequent rehydrogenation of Mg(BH_4)_2 with and without 5 mol % TiF_3 and ScCl_3 have been investigated. Temperature programmed desorption (TPD) experiments revealed a significant increase in the rate of desorption as well as the weight percentage of hydrogen released with additives upon heating to 300 Ā°C. Stable Mg(B_xH_y)_n intermediates were formed at 300 Ā°C, whereas MgB_2 was the major product when heated to 600 Ā°C. These samples were then rehydrogenated and subsequently characterized with powder X-ray diffraction (pXRD), Raman, and NMR spectroscopy. We confirmed significant conversion of MgB_2 to fully hydrogenated Mg(BH_4)_2 for the sample with and without additives. TPD and NMR studies revealed that the additives have a significant effect on the reaction pathway during both dehydrogenation and rehydrogenation reactions. This work suggests that the use of additives may provide a valid pathway for improving intrinsic hydrogen storage properties of magnesium borohydride

    Environmental tobacco smoke and children's health

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    Passive exposure to tobacco smoke significantly contributes to morbidity and mortality in children. Children, in particular, seem to be the most susceptible population to the harmful effects of environmental tobacco smoke (ETS). Paternal smoking inside the home leads to significant maternal and fetal exposure to ETS and may subsequently affect fetal health. ETS has been associated with adverse effects on pediatric health, including preterm birth, intrauterine growth retardation, perinatal mortality, respiratory illness, neurobehavioral problems, and decreased performance in school. A valid estimation of the risks associated with tobacco exposure depends on accurate measurement. Nicotine and its major metabolite, cotinine, are commonly used as smoking biomarkers, and their levels can be determined in various biological specimens such as blood, saliva, and urine. Recently, hair analysis was found to be a convenient, noninvasive technique for detecting the presence of nicotine exposure. Because nicotine/cotinine accumulates in hair during hair growth, it is a unique measure of long-term, cumulative exposure to tobacco smoke. Although smoking ban policies result in considerable reductions in ETS exposure, children are still exposed significantly to tobacco smoke not only in their homes but also in schools, restaurants, child-care settings, cars, buses, and other public places. Therefore, more effective strategies and public policies to protect preschool children from ETS should be consolidated

    Expression of Functional Recombinant Mussel Adhesive Protein Mgfp-5 in Escherichia coli

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    Mussel adhesive proteins have been suggested as a basis for environmentally friendly adhesives for use in aqueous conditions and in medicine. However, attempts to produce functional and economical recombinant mussel adhesive proteins (mainly foot protein type 1) in several systems have failed. Here, the cDNA coding for Mytilus galloprovincialis foot protein type 5 (Mgfp-5) was isolated for the first time. Using this cDNA, we produced a recombinant Mgfp-5 fused with a hexahistidine affinity ligand, which was expressed in a soluble form in Escherichia coli and was highly purified using affinity chromatography. The adhesive properties of purified recombinant Mgfp-5 were compared with the commercial extracted mussel adhesive Cell-Tak by investigating adhesion force using atomic force microscopy, material surface coating, and quartz crystal microbalance. Even though further macroscale assays are needed, these microscale assays showed that recombinant Mgfp-5 has significant adhesive ability and may be useful as a bioadhesive in medical or underwater environments.X119196sciescopu

    Nailing of Intertrochanteric Fractures: Review on Pitfalls and Technical Tips

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    AbstractThe authors describe the advantages and drawbacks of nailing over the dynamic hip screw for the fixation of hip fractures. The technical pitfalls of nailing and the tips to avoid failure of fixation in nailing have been discussed

    Temperature-dependent evolutions of excitonic superfluid plasma frequency in a srong excitonic insulator candidate, Ta2_2NiSe5_5

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    We investigate an interesting anisotropic van der Waals material, Ta2_{2}NiSe5_{5}, using optical spectroscopy. Ta2_{2}NiSe5_{5} has been known as one of the few excitonic insulators proposed over 50 years ago. Ta2_{2}NiSe5_{5} has quasi-one dimensional chains along the aa-axis. We have obtained anisotropic optical properties of a single crystal Ta2_{2}NiSe5_{5} along the aa- and cc-axes. The measured aa- and cc-axis optical conductivities exhibit large anisotropic electronic and phononic properties. With regard to the aa-axis optical conductivity, a sharp peak near 3050 cmāˆ’1^{-1} at 9 K, with a well-defined optical gap (Ī”EIā‰ƒ\Delta^{EI} \simeq 1800 cmāˆ’1^{-1}) and a strong temperature-dependence, is observed. With an increase in temperature, this peak broadens and the optical energy gap closes around āˆ¼\sim325 K(TcEIT_c^{EI}). The spectral weight redistribution with respect to the frequency and temperature indicates that the normalized optical energy gap (Ī”EI(T)/Ī”EI(0)\Delta^{EI}(T)/\Delta^{EI}(0)) is 1āˆ’(T/TcEI)21-(T/T_c^{EI})^2. The temperature-dependent superfluid plasma frequency of the excitonic condensation in Ta2_{2}NiSe5_{5} has been determined from measured optical data. Our findings may be useful for future research on excitonic insulators.Comment: 17 pages, 5 figure

    An integrated database-pipeline system for studying single nucleotide polymorphisms and diseases

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    <p>Abstract</p> <p>Background</p> <p>Studies on the relationship between disease and genetic variations such as single nucleotide polymorphisms (SNPs) are important. Genetic variations can cause disease by influencing important biological regulation processes. Despite the needs for analyzing SNP and disease correlation, most existing databases provide information only on functional variants at specific locations on the genome, or deal with only a few genes associated with disease. There is no combined resource to widely support gene-, SNP-, and disease-related information, and to capture relationships among such data. Therefore, we developed an integrated database-pipeline system for studying SNPs and diseases.</p> <p>Results</p> <p>To implement the pipeline system for the integrated database, we first unified complicated and redundant disease terms and gene names using the Unified Medical Language System (UMLS) for classification and noun modification, and the HUGO Gene Nomenclature Committee (HGNC) and NCBI gene databases. Next, we collected and integrated representative databases for three categories of information. For genes and proteins, we examined the NCBI mRNA, UniProt, UCSC Table Track and MitoDat databases. For genetic variants we used the dbSNP, JSNP, ALFRED, and HGVbase databases. For disease, we employed OMIM, GAD, and HGMD databases. The database-pipeline system provides a disease thesaurus, including genes and SNPs associated with disease. The search results for these categories are available on the web page <url>http://diseasome.kobic.re.kr/</url>, and a genome browser is also available to highlight findings, as well as to permit the convenient review of potentially deleterious SNPs among genes strongly associated with specific diseases and clinical phenotypes.</p> <p>Conclusion</p> <p>Our system is designed to capture the relationships between SNPs associated with disease and disease-causing genes. The integrated database-pipeline provides a list of candidate genes and SNP markers for evaluation in both epidemiological and molecular biological approaches to diseases-gene association studies. Furthermore, researchers then can decide semi-automatically the data set for association studies while considering the relationships between genetic variation and diseases. The database can also be economical for disease-association studies, as well as to facilitate an understanding of the processes which cause disease. Currently, the database contains 14,674 SNP records and 109,715 gene records associated with human diseases and it is updated at regular intervals.</p

    Submerzni uzgoj i karakterizacija polisaharida iz gljive Grifola frondosa ā€“ primjena u kozmetičkoj industriji

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    Grifola frondosa (maitake) is traditionally called \u27the king of mushrooms\u27 and \u27the hen of the woods\u27. Both the fruiting bodies and the mycelium of maitake have been reported to have antitumor and antiviral activities. Recently, submerged culture processes have been developed, with the intention of providing opportunities for increased economic exploitation of maitake. Commonly the aim of these processes is to produce extracellular polysaccharides (EPS), mostly glucans, and to explore their applications, particularly in the cosmetic industry. A wide variety of EPS with different molecular chain length and chemical compositions are produced under different culture conditions. In this article, various biological and physicochemical properties of the EPS of G. frondosa (GF-EPS) are described, with a view to applications in the area of functional cosmeceuticals. The GF-EPS, together with GF mycelial extract (GF-MPS), showed antioxidative activity, stimulation of collagen biosynthetic activity, cell proliferation activity, and inhibitory activity of melanogenesis, without significant cytotoxicity. These diverse functionalities suggest that both GF-EPS and GF-MPS can be promising cosmetic ingredients.Gljivu Grifola frondosa (maitake) u Koreji tradicionalno zovu kraljicom gljiva i Å”umskim bogatstvom. Dokazano je da plodiÅ”te i micelij gljiva maitake imaju antitumorski i antivirusni učinak. Ekonomsko iskoriÅ”tenje te gljive omogućeno je submerznim uzgojem. Uobičajeni je cilj uzgoja proizvodnja ekstracelularnih polisaharida (EPS), uglavnom glukana i istraživanje mogućnosti njihove primjene u kozmetičkoj industriji. Pri raznim uvjetima proizvodnje dobivaju se ekstracelularni polisaharidi različitih duljina lanaca i kemijskoga sastava. U ovom su radu opisana razna bioloÅ”ka i fizikalno-kemijska svojstva ekstracelularnih polisaharida gljive Grifola frondosa (GF-EPS), te primjena u proizvodnji kozmetičkih preparata s povoljnim utjecajem na ljudsko zdravlje. Ekstracelularni polisaharidi i ekstrakt micelija gljive Grifola frondosa (GFMPS) imaju antioksidativni učinak, stimuliraju biosintezu kolagena, bujanje stanica, sprečavaju nastanak melanoma i nemaju jače citotoksično djelovanje, zbog čega su prikladni za primjenu u kozmetičkoj industriji

    Electrochemical performance of YST infiltrated and fe doped YST infiltrated YSZ anodes for IT-SOFC

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    Donor doped and donor-acceptor co-doped strontium titanate perovskite are investigated for intermediate temperature solid oxide fuel cells (IT-SOFCs) anodes. Y0.08Sr0.88TiO3-delta and Y0.08Sr0.92Ti1-xFexO3-delta (x = 0.2, 0.4) anodes were prepared by infiltration in 65% porous yttria stabilized zirconia (YSZ) scaffolds. The microstructure and electrical conductivity of Y0.08Sr0.88TiO3-delta and Y0.08Sr0.92Ti1-xFexO3-delta strongly depends on Fe content. The conductivity of Y0.08Sr0.88TiO3-delta andY(0.08)Sr(0.92)Ti(1-x)Fe(x)O(3-delta); decreases with increasing Fe content in humidified H-2. Y0.08Sr0.88TiO3-delta, Y0.08Sr0.92Ti0.8Fe0.2O3-delta, and Y0.08Sr0.92Ti0.6Fe0.4O3-delta, anodes with a Pd/CeO2 catalyst show peak power density of 298, 421, and 321 mW cm(-2), respectively, in wet H-2 at 1073 K.open0
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